蒸压加气混凝土砌块填充墙的易损性研究

Study on fragility of autoclaved aerated concrete block infills

蒸压加气混凝土砌块填充墙是框架结构和框剪结构中一类常见的非结构构件,在地震中损伤破坏大而修复成本高,对建筑的抗震韧性能力有较大影响。本文基于抗震韧性能力的思想,参考FEMA-P58指南和我国相关规范,通过对国内外大量文献的调研,建立了两组蒸压加气混凝土砌块填充墙的易损性模型:根据墙体破坏程度划分了填充墙的四种性能状态;对比墙体与框架的连接方式对墙体性能的影响,搜集了混凝土框架内刚性连接和混凝土框架内柔性连接两组共41片填充墙的试验数据,建立了两组墙体面内层间位移角和损伤状态发生概率的易损性曲线。研究结果表明:采用柔性连接的填充墙体损伤状态的发生相较于刚性连接的墙体有明显推迟,韧性提升,但传统柔性连接措施尚无法达到“小震不坏”的性能目标。实际应用中通过结构分析得到性能需求参数后,可利用本文提出的易损性模型,预测建筑中实际墙体的损伤状态,在评估建筑整体韧性时更精确地考虑非结构构件的影响。

Autoclaved aerated concrete block infills are common non-structural components in frame structures and frame-shear wall structures.They greatly affect the seismic resilience of buildings due to their vulnerability and high repair cost.In this paper,based on the idea of seismic resilience,referring to FEMA-P58 and China's seismic specifications,two fragility groups of autoclaved aerated concrete(AAC)infills with different constraints conditions are established.First,four performance states of infills are defined.Then,fragility parameters are calculated based on the test data of 41 infills,and fragility curves between story drifts and failure probability are drawn.The statistical results show that the damage of AAC infills with flexible connection is delayed compared with those with rigid connection,and resilience is improved.However,the commonly-used flexible connection cannot achieve the performance target in which the components are undamaged under small earthquakes.In practice,after obtaining story drift through structural analysis,the resilience evaluation method of AAC infills proposed in this paper can be used to predict the damage state of actual walls in buildings and the resilence of the whole building more accurately.